configurator: HAVE_STACK_GROWS_UPWARDS
[ccan] / tools / configurator / configurator.c
1 /* Simple tool to create config.h.
2  * Would be much easier with ccan modules, but deliberately standalone. */
3 #include <stdio.h>
4 #include <stdbool.h>
5 #include <stdlib.h>
6 #include <unistd.h>
7 #include <err.h>
8 #include <sys/types.h>
9 #include <sys/wait.h>
10 #include <sys/stat.h>
11 #include <fcntl.h>
12 #include <string.h>
13
14 #define DEFAULT_COMPILER "cc"
15 #define DEFAULT_FLAGS "-g -Wall -Wundef -Wmissing-prototypes -Wmissing-declarations -Wstrict-prototypes -Wold-style-definition"
16
17 #define OUTPUT_FILE "configurator.out"
18 #define INPUT_FILE "configuratortest.c"
19
20 static int verbose;
21
22 enum test_style {
23         OUTSIDE_MAIN            = 0x1,
24         DEFINES_FUNC            = 0x2,
25         INSIDE_MAIN             = 0x4,
26         DEFINES_EVERYTHING      = 0x8,
27         EXECUTE                 = 0x8000
28 };
29
30 struct test {
31         const char *name;
32         enum test_style style;
33         const char *depends;
34         const char *fragment;
35         bool done;
36         bool answer;
37 };
38
39 static struct test tests[] = {
40         { "HAVE_ALIGNOF", INSIDE_MAIN, NULL,
41           "return __alignof__(double) > 0 ? 0 : 1;" },
42         { "HAVE_ASPRINTF", DEFINES_FUNC, NULL,
43           "#define _GNU_SOURCE\n"
44           "#include <stdio.h>\n"
45           "static char *func(int x) {"
46           "     char *p;\n"
47           "     if (asprintf(&p, \"%u\", x) == -1) p = NULL;"
48           "     return p;\n"
49           "}" },
50         { "HAVE_ATTRIBUTE_COLD", DEFINES_FUNC, NULL,
51           "static int __attribute__((cold)) func(int x) { return x; }" },
52         { "HAVE_ATTRIBUTE_CONST", DEFINES_FUNC, NULL,
53           "static int __attribute__((const)) func(int x) { return x; }" },
54         { "HAVE_ATTRIBUTE_MAY_ALIAS", OUTSIDE_MAIN, NULL,
55           "typedef short __attribute__((__may_alias__)) short_a;" },
56         { "HAVE_ATTRIBUTE_NORETURN", DEFINES_FUNC, NULL,
57           "#include <stdlib.h>\n"
58           "static void __attribute__((noreturn)) func(int x) { exit(x); }" },
59         { "HAVE_ATTRIBUTE_PRINTF", DEFINES_FUNC, NULL,
60           "static void __attribute__((format(__printf__, 1, 2))) func(const char *fmt, ...) { }" },
61         { "HAVE_ATTRIBUTE_UNUSED", OUTSIDE_MAIN, NULL,
62           "static int __attribute__((unused)) func(int x) { return x; }" },
63         { "HAVE_ATTRIBUTE_USED", OUTSIDE_MAIN, NULL,
64           "static int __attribute__((used)) func(int x) { return x; }" },
65         { "HAVE_BIG_ENDIAN", INSIDE_MAIN|EXECUTE, NULL,
66           "union { int i; char c[sizeof(int)]; } u;\n"
67           "u.i = 0x01020304;\n"
68           "return u.c[0] == 0x01 && u.c[1] == 0x02 && u.c[2] == 0x03 && u.c[3] == 0x04 ? 0 : 1;" },
69         { "HAVE_BSWAP_64", DEFINES_FUNC, "HAVE_BYTESWAP_H",
70           "#include <byteswap.h>\n"
71           "static int func(int x) { return bswap_64(x); }" },
72         { "HAVE_BUILTIN_CHOOSE_EXPR", INSIDE_MAIN, NULL,
73           "return __builtin_choose_expr(1, 0, \"garbage\");" },
74         { "HAVE_BUILTIN_CLZ", INSIDE_MAIN, NULL,
75           "return __builtin_clz(1) == (sizeof(int)*8 - 1) ? 0 : 1;" },
76         { "HAVE_BUILTIN_CLZL", INSIDE_MAIN, NULL,
77           "return __builtin_clzl(1) == (sizeof(long)*8 - 1) ? 0 : 1;" },
78         { "HAVE_BUILTIN_CLZLL", INSIDE_MAIN, NULL,
79           "return __builtin_clzll(1) == (sizeof(long long)*8 - 1) ? 0 : 1;" },
80         { "HAVE_BUILTIN_CONSTANT_P", INSIDE_MAIN, NULL,
81           "return __builtin_constant_p(1) ? 0 : 1;" },
82         { "HAVE_BUILTIN_EXPECT", INSIDE_MAIN, NULL,
83           "return __builtin_expect(argc == 1, 1) ? 0 : 1;" },
84         { "HAVE_BUILTIN_FFSL", INSIDE_MAIN, NULL,
85           "return __builtin_ffsl(0L) == 0 ? 0 : 1;" },
86         { "HAVE_BUILTIN_FFSLL", INSIDE_MAIN, NULL,
87           "return __builtin_ffsll(0LL) == 0 ? 0 : 1;" },
88         { "HAVE_BUILTIN_POPCOUNTL", INSIDE_MAIN, NULL,
89           "return __builtin_popcountl(255L) == 8 ? 0 : 1;" },
90         { "HAVE_BUILTIN_TYPES_COMPATIBLE_P", INSIDE_MAIN, NULL,
91           "return __builtin_types_compatible_p(char *, int) ? 1 : 0;" },
92         { "HAVE_BYTESWAP_H", OUTSIDE_MAIN, NULL,
93           "#include <byteswap.h>\n" },
94         { "HAVE_COMPOUND_LITERALS", INSIDE_MAIN, NULL,
95           "char **foo = (char *[]) { \"x\", \"y\", \"z\" };\n"
96           "return foo[0] ? 0 : 1;" },
97         { "HAVE_FOR_LOOP_DECLARATION", INSIDE_MAIN, NULL,
98           "for (int i = 0; i < argc; i++) { return 0; };\n"
99           "return 1;" },
100         { "HAVE_FLEXIBLE_ARRAY_MEMBER", OUTSIDE_MAIN, NULL,
101           "struct foo { unsigned int x; int arr[]; };" },
102         { "HAVE_GETPAGESIZE", DEFINES_FUNC, NULL,
103           "#include <unistd.h>\n"
104           "static int func(void) { return getpagesize(); }" },
105         { "HAVE_LITTLE_ENDIAN", INSIDE_MAIN|EXECUTE, NULL,
106           "union { int i; char c[sizeof(int)]; } u;\n"
107           "u.i = 0x01020304;\n"
108           "return u.c[0] == 0x04 && u.c[1] == 0x03 && u.c[2] == 0x02 && u.c[3] == 0x01 ? 0 : 1;" },
109         { "HAVE_MMAP", DEFINES_FUNC, NULL,
110           "#include <sys/mman.h>\n"
111           "static void *func(int fd) {\n"
112           "     return mmap(0, 65536, PROT_READ, MAP_SHARED, fd, 0);\n"
113           "}" },
114         { "HAVE_NESTED_FUNCTIONS", DEFINES_FUNC, NULL,
115           "void (*func(int val))(int);\n"
116           "void (*func(int val))(int) {\n"
117           "     auto void add(int val2);\n"
118           "     void add(int val2) { val += val2; }\n"
119           "     return add;\n"
120           "}\n" },
121         { "HAVE_STACK_GROWS_UPWARDS", DEFINES_EVERYTHING|EXECUTE, NULL,
122           "static long nest(const void *base, unsigned int i)\n"
123           "{\n"
124           "     if (i == 0)\n"
125           "             return (const char *)&i - (const char *)base;\n"
126           "     return nest(base, i-1);\n"
127           "}\n"
128           "int main(int argc, char *argv[]) {\n"
129           "     return (nest(&argc, argc) > 0) ? 0 : 1\n;"
130           "}\n" },
131         { "HAVE_STATEMENT_EXPR", INSIDE_MAIN, NULL,
132           "return ({ int x = argc; x == argc ? 0 : 1; });" },
133         { "HAVE_TYPEOF", INSIDE_MAIN, NULL,
134           "__typeof__(argc) i; i = argc; return i == argc ? 0 : 1;" },
135         { "HAVE_UTIME", DEFINES_FUNC, NULL,
136           "#include <sys/types.h>\n"
137           "#include <utime.h>\n"
138           "static int func(const char *filename) {\n"
139           "     struct utimbuf times = { 0 };\n"
140           "     return utime(filename, &times);\n"
141           "}" },
142         { "HAVE_WARN_UNUSED_RESULT", DEFINES_FUNC, NULL,
143           "#include <sys/types.h>\n"
144           "#include <utime.h>\n"
145           "static __attribute__((warn_unused_result)) int func(int i) {\n"
146           "     return i + 1;\n"
147           "}" },
148 };
149
150 static char *grab_fd(int fd)
151 {
152         int ret;
153         size_t max, size = 0;
154         char *buffer;
155
156         max = 16384;
157         buffer = malloc(max+1);
158         while ((ret = read(fd, buffer + size, max - size)) > 0) {
159                 size += ret;
160                 if (size == max)
161                         buffer = realloc(buffer, max *= 2);
162         }
163         if (ret < 0)
164                 err(1, "reading from command");
165         buffer[size] = '\0';
166         return buffer;
167 }
168
169 static char *run(const char *cmd, int *exitstatus)
170 {
171         pid_t pid;
172         int p[2];
173         char *ret;
174         int status;
175
176         if (pipe(p) != 0)
177                 err(1, "creating pipe");
178
179         pid = fork();
180         if (pid == -1)
181                 err(1, "forking");
182
183         if (pid == 0) {
184                 if (dup2(p[1], STDOUT_FILENO) != STDOUT_FILENO
185                     || dup2(p[1], STDERR_FILENO) != STDERR_FILENO
186                     || close(p[0]) != 0
187                     || close(STDIN_FILENO) != 0
188                     || open("/dev/null", O_RDONLY) != STDIN_FILENO)
189                         exit(128);
190
191                 status = system(cmd);
192                 if (WIFEXITED(status))
193                         exit(WEXITSTATUS(status));
194                 /* Here's a hint... */
195                 exit(128 + WTERMSIG(status));
196         }
197
198         close(p[1]);
199         ret = grab_fd(p[0]);
200         /* This shouldn't fail... */
201         if (waitpid(pid, &status, 0) != pid)
202                 err(1, "Failed to wait for child");
203         close(p[0]);
204         if (WIFEXITED(status))
205                 *exitstatus = WEXITSTATUS(status);
206         else
207                 *exitstatus = -WTERMSIG(status);
208         return ret;
209 }
210
211 static char *connect_args(char *argv[], const char *extra)
212 {
213         unsigned int i, len = strlen(extra) + 1;
214         char *ret;
215
216         for (i = 1; argv[i]; i++)
217                 len += 1 + strlen(argv[i]);
218
219         ret = malloc(len);
220         len = 0;
221         for (i = 1; argv[i]; i++) {
222                 strcpy(ret + len, argv[i]);
223                 len += strlen(argv[i]);
224                 ret[len++] = ' ';
225         }
226         strcpy(ret + len, extra);
227         return ret;
228 }
229
230 static struct test *find_test(const char *name)
231 {
232         unsigned int i;
233
234         for (i = 0; i < sizeof(tests)/sizeof(tests[0]); i++) {
235                 if (strcmp(tests[i].name, name) == 0)
236                         return &tests[i];
237         }
238         abort();
239 }
240
241 #define PRE_BOILERPLATE "/* Test program generated by configurator. */\n"
242 #define MAIN_START_BOILERPLATE "int main(int argc, char *argv[]) {\n"
243 #define USE_FUNC_BOILERPLATE "(void)func;\n"
244 #define MAIN_BODY_BOILERPLATE "return 0;\n"
245 #define MAIN_END_BOILERPLATE "}\n"
246
247 static bool run_test(const char *cmd, struct test *test)
248 {
249         char *output;
250         FILE *outf;
251         int status;
252
253         if (test->done)
254                 return test->answer;
255
256         if (test->depends && !run_test(cmd, find_test(test->depends))) {
257                 test->answer = false;
258                 test->done = true;
259                 return test->answer;
260         }
261
262         outf = fopen(INPUT_FILE, "w");
263         if (!outf)
264                 err(1, "creating %s", INPUT_FILE);
265
266         fprintf(outf, "%s", PRE_BOILERPLATE);
267         switch (test->style & ~EXECUTE) {
268         case INSIDE_MAIN:
269                 fprintf(outf, "%s", MAIN_START_BOILERPLATE);
270                 fprintf(outf, "%s", test->fragment);
271                 fprintf(outf, "%s", MAIN_END_BOILERPLATE);
272                 break;
273         case OUTSIDE_MAIN:
274                 fprintf(outf, "%s", test->fragment);
275                 fprintf(outf, "%s", MAIN_START_BOILERPLATE);
276                 fprintf(outf, "%s", MAIN_BODY_BOILERPLATE);
277                 fprintf(outf, "%s", MAIN_END_BOILERPLATE);
278                 break;
279         case DEFINES_FUNC:
280                 fprintf(outf, "%s", test->fragment);
281                 fprintf(outf, "%s", MAIN_START_BOILERPLATE);
282                 fprintf(outf, "%s", USE_FUNC_BOILERPLATE);
283                 fprintf(outf, "%s", MAIN_BODY_BOILERPLATE);
284                 fprintf(outf, "%s", MAIN_END_BOILERPLATE);
285                 break;
286         case DEFINES_EVERYTHING:
287                 fprintf(outf, "%s", test->fragment);
288                 break;
289         default:
290                 abort();
291
292         }
293         fclose(outf);
294
295         if (verbose > 1)
296                 if (system("cat " INPUT_FILE) == -1);
297
298         output = run(cmd, &status);
299         if (status != 0 || strstr(output, "warning")) {
300                 if (verbose)
301                         printf("Compile %s for %s, status %i: %s\n",
302                                status ? "fail" : "warning",
303                                test->name, status, output);
304                 if (test->style & EXECUTE)
305                         errx(1, "Test for %s did not compile:\n%s",
306                              test->name, output);
307                 test->answer = false;
308                 free(output);
309         } else {
310                 /* Compile succeeded. */
311                 free(output);
312                 /* We run INSIDE_MAIN tests for sanity checking. */
313                 if ((test->style & EXECUTE) || (test->style & INSIDE_MAIN)) {
314                         output = run("./" OUTPUT_FILE, &status);
315                         if (!(test->style & EXECUTE) && status != 0)
316                                 errx(1, "Test for %s failed with %i:\n%s",
317                                      test->name, status, output);
318                         if (verbose && status)
319                                 printf("%s exited %i\n", test->name, status);
320                         free(output);
321                 }
322                 test->answer = (status == 0);
323         }
324         test->done = true;
325         return test->answer;
326 }
327
328 int main(int argc, char *argv[])
329 {
330         char *cmd;
331         char *default_args[] = { "", DEFAULT_COMPILER, DEFAULT_FLAGS, NULL };
332         unsigned int i;
333
334         if (argc > 1) {
335                 if (strcmp(argv[1], "--help") == 0) {
336                         printf("Usage: configurator [-v] [<compiler> <flags>...]\n"
337                                "  <compiler> <flags> will have \"-o <outfile> <infile.c>\" appended\n"
338                                "Default: %s %s\n",
339                                DEFAULT_COMPILER, DEFAULT_FLAGS);
340                         exit(0);
341                 }
342                 if (strcmp(argv[1], "-v") == 0) {
343                         argc--;
344                         argv++;
345                         verbose = 1;
346                 } else if (strcmp(argv[1], "-vv") == 0) {
347                         argc--;
348                         argv++;
349                         verbose = 2;
350                 }
351         }
352
353         if (argc == 1)
354                 argv = default_args;
355
356         cmd = connect_args(argv, "-o " OUTPUT_FILE " " INPUT_FILE);
357         for (i = 0; i < sizeof(tests)/sizeof(tests[0]); i++)
358                 run_test(cmd, &tests[i]);
359
360         unlink(OUTPUT_FILE);
361         unlink(INPUT_FILE);
362
363         cmd[strlen(cmd) - strlen(" -o " OUTPUT_FILE " " INPUT_FILE)] = '\0';
364         printf("/* Generated by CCAN configurator */\n"
365                "#ifndef CCAN_CONFIG_H\n"
366                "#define CCAN_CONFIG_H\n");
367         printf("#define _GNU_SOURCE /* Always use GNU extensions. */\n");
368         printf("#define CCAN_COMPILER \"%s\"\n", argv[1]);
369         printf("#define CCAN_CFLAGS \"%s\"\n\n", cmd + strlen(argv[1]) + 1);
370         for (i = 0; i < sizeof(tests)/sizeof(tests[0]); i++)
371                 printf("#define %s %u\n", tests[i].name, tests[i].answer);
372         printf("#endif /* CCAN_CONFIG_H */\n");
373         return 0;
374 }